Sign Language FAQ
Is Sign Language universally understandable as for example English in the former British Colonies?

There is no difference whether one is deaf or not when tongues are alien to our knowledge and experience. Each form of sign language has developed in its own region related to the greater culture of that region and therefore naturally could not be universal, however visual gestures combined with expressions as an only means of communication together with intelligence, gives the edge to Deaf people in this situation.

Everybody has its own language, Deaf and hearing alike. Common ground might be found in vocabulary and that is about it.